1. Field of the Invention
The present invention relates to a freezing cycle apparatus having quick freezing and thawing functions, and in particular to an improved freezing cycle apparatus having quick freezing and thawing functions by which it is possible to selectively use a function between a quick freezing function and a quick thawing function for a refrigerator.
2. Description of the Conventional Art
As shown in FIG. 1, a conventional freezing cycle apparatus includes a compressor 1 for changing a gaseous refrigerant of a low temperature and pressure to a high temperature and pressure gaseous refrigerant, an condenser 2 for changing the thusly changed high temperature and pressure gaseous refrigerant to a high temperature and pressure liquid state refrigerant which acts and radiating heat to the outside of the refrigerator, a capillary tube 3 for changing the liquid state refrigerant into a low temperature and pressure liquid refrigerant, an evaporator 4 for changing the liquid state refrigerant which is changed to a low temperature and pressure by the capillary tube 3 to a gaseous state refrigerant, thus absorbing external heat, and a refrigerant tube 5 connecting the condenser 1, the compressor 2, the capillary tube 3, and the evaporator 4, respectively.
The above-described refrigerating cycle is generally adapted to a refrigerator or an air conditioner and is directed to storing foods in a fresh state and conditioning an indoor environment by cooling or heating the indoor air by installing the evaporator 4 which absorbs an external heat and the compressor, which 2 externally radiates the thusly absorbed heat.
The refrigerating cycle may have a quick freezing or quick thawing function. The quick freezing and quick thawing function will be explained in more detail with reference to FIG. 2. In a refrigerator having a fan 11 and an evaporator 12 which are installed behind a grill fan (not shown) in a freezing chamber 10, in the quick freezing mode of the conventional refrigerator, as shown in FIG. 3, the air cooled by the evaporator 12 is introduced into the freezing chamber 10 forcibly by the fan 11. The thusly introduced cooled air flows toward the evaporator 12 through the paths formed in the refrigerating chamber 10.
Namely, a damper 14 for the freezing chamber 15 is operated by a selection switch (not shown) or a selection button (not shown). When the damper 14 is closed, the cooled air flowing into the refrigerating chamber 15 is blocked, and only the freezing chamber 10 is operated.
However, in the freezing cycle of the conventional quick freezing refrigerator which is operated identically to a state that the refrigerator is normally operated, since a damper is installed in the refrigerator for controlling the amount of refrigerant, thus operating only the freezing chamber. Therefore, 3 (three) hours are required for the quick freezing operation, assuming that a standard test package having a thickness of 5 cm and a weight of 500 g is used for attempting to decrease a temperature from -5.degree. C to -1.degree. C. within 30 minutes. Therefore, it is impossible to actually enable a quick freezing operation within 30 minutes which is required for fully preventing the expansion of a water molecular structure contained in the food to be frozen.
In addition, the conventional apparatus which is configured to include a quick freezing and quick thawing cycle will now be explained.
First, the cycle of the conventional freezing cycle apparatus having a quick thawing function will now be explained with reference to FIG. 4 which is performed as follows: the compressor 1 the condenser 2 a first capillary tube 3 an opening/closing valve 8 a main evaporator 4 a check valve 9 a compressor 1, so that the common freezing function is performed. Here, a first cycle is defined as one circulation during which the common refrigerating function is performed once.
At this time, a second capillary tube 7 is connected between the first capillary tube 3 and the opening/closing valve 8, and an auxiliary evaporator 6 is connected with one end of the second capillary tube 7.
The other end of the auxiliary evaporator 6 is connected between the compressor 1 and the check valve 9.
The quick freezing cycle of the freezing cycle apparatus having a quick freezing function is performed as follows: the compressor 1 the condenser 2 the first capillary tube 3 the second capillary tube 7 the auxiliary evaporator 6 the compressor 1, thus performing the quick freezing function.
At this time, the refrigerant which became a low temperature and pressure by the first capillary tube 3 passes through the second capillary tube 7, and the pressure thereof is decreased thereby, and then the refrigerant passes through the auxiliary evaporator 6, so that the quick freezing function (here, the cycle of performing the quick freezing function is called as a second cycle) is performed.
However, when performing a quick freezing operation using the freezing cycle apparatus having a conventional quick freezing function, since the refrigerant does not flow to the main evaporator, when the apparatus is operated for more than a predetermined time, the temperature of the interiors of the freezing chamber and refrigerating chamber in which the main evaporator is installed is increased.
In addition, the cycle of the freezing cycle apparatus having a conventional quick thawing function is performed as follows: the compressor 1 a three-way valve 8 the condenser 2 the check valve 9 the first capillary tube 3 the evaporator 4 the compressor 1, for thus performing a common freezing function.
During the freezing cycle, the gaseous refrigerant is changed to a liquid state refrigerant by the condenser 2, thus radiating heat to the output side of the refrigerator.
At this time, in order to perform the quick thawing function, an auxiliary condenser 6 is connected with the three-way valve 8 for performing a quick thawing function. The second capillary tube 7 is connected with an end portion of the auxiliary condenser 6, and the other end of the second capillary tube 7 is connected between the check valve 9 and the first capillary tube 3.
The quick thawing cycle of the freezing cycle apparatus having a conventional quick thawing function is performed as follows: the compressor 1 the three-way valve 8 the auxiliary condenser 6 the second capillary tube 7 the first capillary tube 3 the main evaporator 4 the compressor 1, for thus performing a quick thawing function (here, the above-described cycle is called as a third cycle in which the quick thawing cycle is performed).
However, as described above, in order to concurrently perform the quick freezing and quick thawing operations, an additional cycle should be disadvantageously performed.